diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/CodeGen/GlobalMerge.cpp | 32 | ||||
| -rw-r--r-- | llvm/test/Transforms/GlobalMerge/basic.ll | 21 |
2 files changed, 38 insertions, 15 deletions
diff --git a/llvm/lib/CodeGen/GlobalMerge.cpp b/llvm/lib/CodeGen/GlobalMerge.cpp index 9f7f5e392a9..f4526c64f1e 100644 --- a/llvm/lib/CodeGen/GlobalMerge.cpp +++ b/llvm/lib/CodeGen/GlobalMerge.cpp @@ -461,7 +461,18 @@ bool GlobalMerge::doMerge(const SmallVectorImpl<GlobalVariable *> &Globals, unsigned CurIdx = 0; for (j = i; j != -1; j = GlobalSet.find_next(j)) { Type *Ty = Globals[j]->getValueType(); + + // Make sure we use the same alignment AsmPrinter would use. There + // currently isn't any helper to compute that, so we compute it + // explicitly here. + // + // getPreferredAlignment will sometimes return an alignment higher + // than the explicitly specified alignment; we must ignore that + // if the section is explicitly specified, to avoid inserting extra + // padding into that section. unsigned Align = DL.getPreferredAlignment(Globals[j]); + if (Globals[j]->hasSection() && Globals[j]->getAlignment()) + Align = Globals[j]->getAlignment(); unsigned Padding = alignTo(MergedSize, Align) - MergedSize; MergedSize += Padding; MergedSize += DL.getTypeAllocSize(Ty); @@ -516,6 +527,7 @@ bool GlobalMerge::doMerge(const SmallVectorImpl<GlobalVariable *> &Globals, GlobalVariable::NotThreadLocal, AddrSpace); MergedGV->setAlignment(MaxAlign); + MergedGV->setSection(Globals[i]->getSection()); const StructLayout *MergedLayout = DL.getStructLayout(MergedTy); for (ssize_t k = i, idx = 0; k != j; k = GlobalSet.find_next(k), ++idx) { @@ -599,16 +611,15 @@ bool GlobalMerge::doInitialization(Module &M) { IsMachO = Triple(M.getTargetTriple()).isOSBinFormatMachO(); auto &DL = M.getDataLayout(); - DenseMap<unsigned, SmallVector<GlobalVariable *, 16>> Globals, ConstGlobals, - BSSGlobals; + DenseMap<std::pair<unsigned, StringRef>, SmallVector<GlobalVariable *, 16>> + Globals, ConstGlobals, BSSGlobals; bool Changed = false; setMustKeepGlobalVariables(M); // Grab all non-const globals. for (auto &GV : M.globals()) { // Merge is safe for "normal" internal or external globals only - if (GV.isDeclaration() || GV.isThreadLocal() || - GV.hasSection() || GV.hasImplicitSection()) + if (GV.isDeclaration() || GV.isThreadLocal() || GV.hasImplicitSection()) continue; // It's not safe to merge globals that may be preempted @@ -623,6 +634,7 @@ bool GlobalMerge::doInitialization(Module &M) { assert(PT && "Global variable is not a pointer!"); unsigned AddressSpace = PT->getAddressSpace(); + StringRef Section = GV.getSection(); // Ignore all 'special' globals. if (GV.getName().startswith("llvm.") || @@ -637,26 +649,26 @@ bool GlobalMerge::doInitialization(Module &M) { if (DL.getTypeAllocSize(Ty) < MaxOffset) { if (TM && TargetLoweringObjectFile::getKindForGlobal(&GV, *TM).isBSSLocal()) - BSSGlobals[AddressSpace].push_back(&GV); + BSSGlobals[{AddressSpace, Section}].push_back(&GV); else if (GV.isConstant()) - ConstGlobals[AddressSpace].push_back(&GV); + ConstGlobals[{AddressSpace, Section}].push_back(&GV); else - Globals[AddressSpace].push_back(&GV); + Globals[{AddressSpace, Section}].push_back(&GV); } } for (auto &P : Globals) if (P.second.size() > 1) - Changed |= doMerge(P.second, M, false, P.first); + Changed |= doMerge(P.second, M, false, P.first.first); for (auto &P : BSSGlobals) if (P.second.size() > 1) - Changed |= doMerge(P.second, M, false, P.first); + Changed |= doMerge(P.second, M, false, P.first.first); if (EnableGlobalMergeOnConst) for (auto &P : ConstGlobals) if (P.second.size() > 1) - Changed |= doMerge(P.second, M, true, P.first); + Changed |= doMerge(P.second, M, true, P.first.first); return Changed; } diff --git a/llvm/test/Transforms/GlobalMerge/basic.ll b/llvm/test/Transforms/GlobalMerge/basic.ll index c6924f9a104..4244ae77031 100644 --- a/llvm/test/Transforms/GlobalMerge/basic.ll +++ b/llvm/test/Transforms/GlobalMerge/basic.ll @@ -3,18 +3,29 @@ target datalayout = "e-p:64:64" target triple = "x86_64-unknown-linux-gnu" -; CHECK: @_MergedGlobals = private global <{ i32, i32 }> <{ i32 1, i32 2 }>, align 4 +; CHECK: @_MergedGlobals = private global <{ i32, i32 }> <{ i32 3, i32 4 }>, section "foo", align 4 +; CHECK: @_MergedGlobals.1 = private global <{ i32, i32 }> <{ i32 1, i32 2 }>, align 4 -; CHECK: @a = internal alias i32, getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals, i32 0, i32 0) +; CHECK-DAG: @a = internal alias i32, getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals.1, i32 0, i32 0) @a = internal global i32 1 -; CHECK: @b = internal alias i32, getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals, i32 0, i32 1) +; CHECK-DAG: @b = internal alias i32, getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals.1, i32 0, i32 1) @b = internal global i32 2 +; CHECK-DAG: @c = internal alias i32, getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals, i32 0, i32 0) +@c = internal global i32 3, section "foo" + +; CHECK-DAG: @d = internal alias i32, getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals, i32 0, i32 1) +@d = internal global i32 4, section "foo" + define void @use() { - ; CHECK: load i32, i32* getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals, i32 0, i32 0) + ; CHECK: load i32, i32* getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals.1, i32 0, i32 0) %x = load i32, i32* @a - ; CHECK: load i32, i32* getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals, i32 0, i32 1) + ; CHECK: load i32, i32* getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals.1, i32 0, i32 1) %y = load i32, i32* @b + ; CHECK: load i32, i32* getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals, i32 0, i32 0) + %z1 = load i32, i32* @c + ; CHECK: load i32, i32* getelementptr inbounds (<{ i32, i32 }>, <{ i32, i32 }>* @_MergedGlobals, i32 0, i32 1) + %z2 = load i32, i32* @d ret void } |
